Corrugated fin

ABSTRACT

A corrugated fin for a composite heat exchanger for motor vehicles include a condenser portion and a radiator portion. The radiator portion is larger in fin width than the condenser portion. The condenser portion and the radiator portion have respectively first and second louvers formed corresponding to the fin widths. The first and second louvers respectively have first and second louver slats inclined in a direction which is different for each of the condenser portion and the radiator portion to oppose each other, and an inclination angle of the second louver slats is smaller than an inclination angle of the first louver slats.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention belongs to a technical field of acorrugated fin for composite heat exchangers.

[0003] 2. Description of the Related Art

[0004] The conventional corrugated fin corresponds to required heatrelease amounts of respective heat exchangers by making the fin widthand the number of louver slats different between a condenser side and aradiator side. (For example, refer to Japanese Patent Laid-open No. Hei10-253276.)

[0005] Regarding composite heat exchangers used particularly for motorvehicles, there has been a demand to make thicknesses of the condenserand the radiator which compose the composite heat exchanger differentaccording to diversification of the size of cabin and diversification ofrequired specification of cooling performance in an engine room. In thiscase, the corrugated fin should be made to have different fin widthbetween the condenser side and the radiator side. However, theconventional corrugated fin have such a problem that, when the finwidths of the corrugated fin integrally formed with corrugated fin ofthe composite heat exchanger are made different from each other, theentire corrugated fin bend during a corrugating step due to a differenceof residual stresses generated in a louver processing step due to adifference of the number of louver slats formed according to the finwidth.

SUMMARY OF THE INVENTION

[0006] An object of the present invention is to provide a corrugated finwhich integrally has two types of fin widths respectively made differentcorresponding to two types of heat exchangers, the corrugated finscapable of preventing bending of the entire corrugated fin during acorrugating step thereof due to a residual stress generated in a louverprocessing step.

[0007] Another object of the present invention is to provide amanufacturing method of a corrugated fin which integrally has two typesof fin widths respectively made different corresponding to two types ofheat exchangers, the corrugated fins capable of preventing bending ofthe entire corrugated fin during a corrugating step thereof due to aresidual stress generated in a louver processing step.

[0008] In order to achieve the first object, the corrugated finaccording to the present invention comprises: a first and secondcorrugated fin portions having different fin widths corresponding to twotypes of heat exchangers and integrally formed next to each other, thefin width (L_(A)) of the first corrugated fin portion being smaller thanthe fin width of the second corrugated fin portion ; and a first andsecond louvers provided on each of the first and second corrugated finportions to extend corresponding to the fin widths of the first andsecond corrugated fin portions, the first and second louversrespectively having a plurality of louver slats inclined at apredetermined angle, the louver slats respectively having a direction ofinclination which is different between each of the first and secondcorrugated fin portions, and a processed amount per unit width of thesecond louver being smaller than a processed amount per unit width ofthe first louver.

[0009] On the corrugated fin, the residual stress per unit widthgenerated in a louver processing step is reduced by making the processedamount per unit width of the second louver on the second corrugated finportion smaller than the processed amount per unit width of the firstlouver on the first corrugated fin portion. Accordingly, degree ofintensity of the residual stress becomes low, and a combination of thelarger fin width and the louver having the more louver slats with theresidual stress of small intensity can be substantially balanced with acombination of the smaller fin width and the louver having the lesslouver slats with the residual stress of large intensity, therebypreventing the bending of the entire corrugated fin in a processing stepthereafter.

[0010] Thus, the two types of corrugated fin portion can be made to havedifferent fin widths to thereby meet diversified demands forperformance.

[0011] In the above corrugated fin, an inclination angle of the secondlouver on the second corrugated fin portion is preferably smaller thanan inclination angle of the first louver on the first corrugated finportion so that the processed amount per unit width of the second louverbecomes smaller than the first louver.

[0012] This results in that the combination of the larger fin width andthe second louver having the more louver slats with the residual stressof small intensity can be substantially balanced with the combination ofthe smaller fin width and the first louver having the less louver slatswith the residual stress of large intensity, thereby preventing thebending of the entire corrugated fins in the processing step thereafter.

[0013] Since the second louver on the second corrugated fin portion hasthe smaller inclination angle, excellent cooling performance can beobtained due to smooth air flow, even though the louver has the largenumber of louver slats.

[0014] Thus, the two types of corrugated fin portions can be made tohave different fin widths to thereby meet the diversified demands forperformance and improve heat exchange performance.

[0015] Further, in the above corrugated fin, a pitch between adjacentlouver slats of the second louver formed on the second corrugated finportion is preferably narrower than a pitch between the adjacent louverslats of the first louver formed on the first corrugated fin portion sothat the processed amount per unit width of the second louver becomessmaller than the first louver.

[0016] This results in that the combination of the larger fin width andthe second louver having the more louver slats with the residual stressof small intensity can be substantially balanced with the combination ofthe smaller fin width and the first louver having the less louver slatswith the residual stress of large intensity, thereby preventing thebending of the entire corrugated fins in the processing step thereafter.

[0017] Further, in the above corrugated fin, the second louver of thesecond corrugated fin having the larger fin width has an increased heatrelease area to contact with the air flow, so that the excellent coolingperformance can be obtained.

[0018] Thus, the two types of corrugated fin portions can be made tohave different fin widths to thereby meet the diversified demands forperformance and improve heat exchange performance.

[0019] Further, on the corrugated fin, the first corrugated fin portionis preferably for automotive condensers, and the second corrugated finportion is preferably for automotive radiators.

[0020] This results in that the fin widths of the condenser portion andthe radiator portion of the composite heat exchanger can correspond torespective demands for the cooling performance and to diversified motorvehicles while reducing the cost.

[0021] In order to achieve the second object, the manufacturing methodof the corrugated fins according to the present invention comprises: alouver processing step to form a first and second louvers in such amanner that on each of a first and second corrugated fin portions haverespectively different fin widths corresponding to two types of heatexchangers and integrally formed next to each other, the fin width ofthe first corrugated fin portion being smaller than the fin width of thesecond corrugated fin portion, the first and second louvers extendingcorresponding to the fin widths of the first and second corrugated finportions and having a plurality of louver slats inclined at apredetermined angle respectively, the louver slats respectively having adirection of inclination which is different between each of the firstand second corrugated fin portions, and a processed amount per unitwidth of the second corrugated fin portion is smaller than a processedamount per unit width of the first corrugated fin portion; and a bendcorrecting step to correct, after the louver processing step, a bend ofentire body of the first and second corrugated fin portions by wideningto a predetermined width a wave pitch inside a bending direction of thefirst and second corrugated fin portions which are formed entirely in acorrugated form

[0022] In the manufacturing method of the corrugated fin, when two typesof corrugated fin portions having different fin widths are corrugated toform the corrugated fin, the bend of the corrugated fin is corrected bywidening to the predetermined width the wave pitch inside the bendingdirection of the corrugated fin which tend to bend entirely whencorrugated. Accordingly, the bends can be further corrected andminimized, and the two types of the corrugated fin portions can havedifferent fin widths, thereby meeting the diversified demands forperformance.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023]FIG. 1 is an explanatory view showing a part of a composite heatexchanger using corrugated fins of a first embodiment;

[0024]FIG. 2 is an enlarged view of the corrugated fins of the firstembodiment;

[0025]FIG. 3 is a schematic view showing a cross-section of thecorrugated fins of the first embodiment;

[0026]FIG. 4 is an explanatory view showing a corrugated fin correctingdevice used for manufacturing the corrugated fin of the firstembodiment;

[0027]FIG. 5 is a cross-sectional explanatory view of a corrugated finof a second embodiment; and

[0028]FIGS. 6A and 6B are explanatory views of manufacturing method ofthe corrugated fin according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, embodiments for realizing a corrugated fin of thepresent invention will be described based on the drawings.

First Embodiment

[0030] First, a structure will be explained.

[0031]FIG. 1 is an explanatory view showing a part of a composite heatexchanger using a corrugated fin of a first embodiment. FIG. 2 is anenlarged view of the corrugated fin of the first embodiment. FIG. 3 is aschematic view showing a cross-section of the corrugated fin of thefirst embodiment.

[0032] As shown in FIG. 1 to FIG. 3, a composite heat exchanger 1includes plural corrugated fins 2 respectively having a condenserportion 21, and a radiator portion 22, and tubes 3 arranged betweenthese corrugated fins 2.

[0033] The first embodiment is an example of the corrugated fins 2 whichare used for the composite heat exchanger 1 which comprises a condenser5 and a radiator 6 arranged in a parallel relationship with each otherand mounted in a motor vehicle.

[0034] The corrugated fin 2 is, as shown in FIG. 2, integrally formed ofthe condenser portion 21, corresponding to a first corrugated finportion of the present invention, used as the corrugated fin of thecondenser 5 and the radiator portion 22, corresponding to a secondcorrugated fin portion of the present invention, used as the corrugatedfin of the radiator 6.

[0035] Further, in FIG. 2, for the corrugated fin 2, the fin width ofthe condenser portion 21 is denoted by L_(A), the fin width of theradiator portion 22 is denoted by L_(B), a wave pitch is denoted by F, awave height is denoted by h. The fin width L_(B) of the radiator portion22 is larger than the fin width L_(A) of the condenser portion 21.

[0036] The corrugated fin 2 with the condenser portion 21 and theradiator portion 22 is formed based on a long plate on which, first, afirst louver 211 is formed at a predetermined pitch on the condenserportion 21. The first louver 211 has a plurality of louver slats 211 aformed by opening and raising a portion of the long plate correspondingto the fin width L_(A) of the condenser portion 21, the louver slats 211a being processed to be inclined against the long plate at apredetermined inclination angle A.

[0037] In the first embodiment, the number of louver slats 211 a of thefirst louver 211 formed on the condenser portion 21 is 16, and theinclination angle A of the first louver slats 211 a is 23°.

[0038] Meanwhile, a second louver 221 is formed at a predetermined pitchon the radiator portion 22 of the long plate. The second louver 221 isformed by a plurality of louver slats 221 a corresponding to the finwidth L_(B) of the radiator portion 22, the louver slats being processedto be inclined against the long plate at a predetermined inclinationangle B.

[0039] In the first embodiment, the number of louver slats 221 a of thesecond louver 221 formed on the radiator portion 22 is 27, and theinclination angle B of the second louver slats 221 a is 20°.

[0040] Further, the first and second louver slats 211 a and 221 a of thefirst and second louver 211 and 221 are inclined in different directionswhich oppose each other.

[0041] The plate on which the first and second louvers 211 and 221 areformed is corrugated by processing to thereby form the corrugated fin 2.Then plural layers of these corrugated fins 2 are arranged between thetubes 3 to compose the composite heat exchanger 1.

[0042] Here, in manufacturing the corrugated fin 2, prevention ofbending of the corrugated fins 2 during formation of the corrugated fins2 is, if necessary, carried out as follows.

[0043] The first and second louvers 211 and 221 formed on the condenserportion 21 and the radiator portion 22 of the corrugated fin 2respectively have the different number of louver slats 211 a and 221 ato be 16 and 27, which causes different residual stresses to remain atprocessed portions and in the vicinity thereof during processing offorming the louver slats 211 a and 221 a by opening and rising theportion of the long plate. However, on the corrugated fin 2 in the firstembodiment, the second louver slats 221 a of the second louver 221 ofthe radiator portion 22, which are formed so many as 27, have a smallinclination angle of 20° so as to make the processed amount of raisingthe second louver slats 221 a smaller than the first louver slats 211 aof the first louver 211 of the condenser portion 21. The intensity ofthe residual stress per unit width is thus adjusted so that the sums ofthe respective residual stresses of the condenser portion 21 and theradiator portion 22 become approximately equal. This adjustment to theinclination angles of the first and second louver slats 211 a and 221 acan prevent the bending of the entire corrugated fin 2 during the abovementioned corrugating process thereafter.

[0044] After the louver processing step, as shown in FIG. 4, thecorrugated fin 2 in the first embodiment are passed through betweenrollers 41 of a corrugated fin correcting device 4, which has the pluralrollers 41 at a predetermined pitch. Consequently, the corrugated fins 2are obtained with high precision of linearity and the fin pitch is madeto be a predetermined width so that the corrugated fin 2 can beprecisely assembled to the composite heat exchanger 1 thereafter.

[0045] On the thus formed corrugated fin 2, the inclination angle B ofthe second louver 221 of the radiator portion 22 is small, so the airflows smoothly even when the fin width L_(B) of the radiator portion 22is made larger, and thus the cooling performance can be improved withoutimpairing the effect of making the fin width L_(B) larger.

[0046] The corrugated fin 2 of the first embodiment can provide effectsas listed below.

[0047] (1) The radiator portion 22 and the condenser portion 21 of thefirst and second corrugated fin 2 having two different fin widths of thecomposite heat exchanger 1 for motor vehicles are formed integrally nextto each other. The first and second louver slats 211 a and 221 a areformed by opening and rising process to have numbers of 16 and 27respectively, corresponding to the fin widths L_(A) and L_(B) on thecondenser portion 21 and the radiator portion 22, the first louver slats211 a of the condenser portion 21 is made to be inclined at theinclination angle of 23°, the second louver slats 221 a of the radiatorportion 22 is made to be inclined at the inclination angle of 20°, andthe inclination directions of the first and second louver slats 211 aand 221 a are made different opposing each other. The bending of theentire corrugated fin 2 is prevented by making the processed amount perunit width of the second louver 221 on the radiator portion 22 havingthe larger fin width smaller than the processed amount per unit width ofthe first louver 211 on the first condenser portion 21 having thesmaller fin width. Consequently, the two portions 21 and 22 of thecorrugated fin 2 can have the different fin widths L_(A) and L_(B) tothereby meet diversified demands for performance.

[0048] (2) On the condenser portion 21 and the radiator portion 22having two different fin widths of the composite heat exchanger 1 formotor vehicles, the condenser portion 21 is inclined at the angle of 23°and the radiator portion 22 is inclined at the angle of 20°, and theangle of the second louver slats 221 a of the radiator portion 22 havingthe larger fin width L_(B) is made smaller than the angle of the firstlouver slats 211 a of the condenser portion 22 having the smaller finwidth L_(A), so that the two portions 21 and 22 are made to haveinclination angles corresponding to the different fin widths L_(A) andL_(B), thereby meeting the diversified demands for performance andimproving heat exchange performance.

[0049] (4) For the condenser portion 21 of the corrugated fin 2 used forautomotive condensers and the radiator portion 22 of the corrugated fin2 used for automotive radiators, the inclination angles of the first andsecond louver slats 211 a and 221 a are set corresponding to the finwidths L_(A) and L_(B) for the condenser 5 and the radiator 6 of thecomposite heat exchanger 1, thereby corresponding to respective demandsfor cooling performance and to the diversified motor vehicles whilereducing the cost.

Second Embodiment

[0050] In a second embodiment, as shown in FIG. 5, a condenser portion21 corresponding to a first corrugated fin portion of the presentinvention has a fin width P_(A) smaller than a fin width P_(B) of aradiator portion 22 corresponding to a second corrugated fin portion ofthe present invention. The condenser portion 21 and the radiator portion22 has a first and second louvers 21 and 22 respectively. The first andsecond louvers 21 and 22 are formed with a first and second louver slats211 a and 221 a respectively. A pitch P_(B) of the second louver slats221 a of the second louver 221 of the radiator portion 22 is madesmaller than a pitch P_(A) of a first louver slats 211 a of the firstlouver 21 of the condenser portion 21.

[0051] Incidentally, the other structure is the same as that of thecorrugated fins 2 of the first embodiment, so the explanation thereof isomitted.

[0052] Here, prevention of bending of the corrugated fins 2 duringformation of the corrugated fin 2 is, if necessary, carried out asfollows.

[0053] By narrowing the pitch P_(B) of the second louver slats 221 a ofthe radiator portion 22 than the pitch P_(A) of the condenser portion21, the corrugated fin 2 of the second embodiment reduces a processedamount of raising the second louver slats 221 a to a predeterminedinclination angle when forming the second louver 221 so as to equalizeintensity of residual stress per unit width on the radiator portion 22with intensity of residual stress per unit width remaining on thecondenser portion 21, thereby preventing bending of the corrugated fin 2during a corrugating step thereafter.

[0054] The corrugated fin 2 of the second embodiment can provide thefollowing effects in addition to the effects (1) and (4) of the firstembodiment.

[0055] (3) By narrowing the pitch P_(B) between each second louver slats221 a of the second louver 221 of the radiator portion 22 having the finwidth L_(B) larger than the fin width P_(A) of the first louver slats211 a of the condenser portion 21, the two portions 21 and 22 ofcorrugated fin 2 can have different fin widths, thereby meetingdiversified demands for performance.

[0056] Incidentally, a manufacturing method of the corrugated fin 2 tocorrect a bend of the entire corrugated fin 2 thereafter will beexplained.

[0057] When forming the corrugated fin 2, the bend of the entirecorrugated fin 2 generated during the corrugating processing isthereafter corrected using a corrugated fin correcting device 4 shown inFIG. 4 in such a manner that when the corrugated fin 2 is passed throughbetween rollers 41 which is arranged at a predetermined pitch andopposing each other, a circumferential speed of the roller inside thebending (a pitch F₂ side shown in FIG. 6A) is made faster than that ofthe opposing side (a pitch F₁ side shown in FIG. 6A). Consequently, asshown in FIG. 6B, a pitch F₂₁ in a corrugated form inside the bending iswiden to be substantially the same pitch as F₁ to correct the entirebend, and the fin width F₂ before the formation is 48 mm and the finwidth F₂₁ after the formation is 47.5 mm. Incidentally, the other effectand structure are the same as those of the first embodiment, so theexplanation thereof is omitted.

[0058] The method thus used to correct the bend of the corrugated fin 2can provide the following effects in addition to the effects (1) and (2)of the first embodiment.

[0059] (5) For a composite heat exchanger 1 for motor vehicles, thecondenser portion 21 and the radiator portion 22 are integrally formednext to each other to have different fin widths, and the bend of theentire corrugated fin 2 during the corrugating step is correctedthereafter by widening the wave pitch inside the bending to apredetermined width. Accordingly, the bending can be further correctedand minimized, and the two portions 21 and 22 of the corrugated fin 2can have different fin widths, thereby meeting diversified demands forperformance.

[0060] Further, this corrugated fin 2 correcting device 4 used incombination with the first embodiment and the second embodiment canlimit the bending of the corrugated fin 2 with high precision, which canthus contribute to efficient manufacturing during the manufacturing stepof the composite heat exchanger 1 thereafter, and to increase of theproduct precision of the composite heat exchanger 1.

[0061] As described above, the corrugated fin of the present inventionhave been explained based on the first embodiment and the secondembodiment. However, the specific structure is not limited to theseexamples, and modification or addition of design will be toleratedwithout departing from the gist of the invention according to therespective claims.

[0062] For example, in the examples, the louvers are formed to beorthogonal to the air passing through the corrugated fin, but thelouvers may be formed to have an angle to the air passing through thecorrugated fin. In this case, the condenser side and the radiator sidemay have the same direction or a different direction, and may have thesame angle or a different angle.

[0063] Further, when changing the wave pitch of the corrugated fin, thecorrugated fin is passed through between the rollers having apredetermined width in the examples, but the corrugated fin may bepressed to lower the wave height.

[0064] The entire contents of Japanese Patent Application 2002-309952(filed Oct. 24, 2002) are incorporated herein by reference.

[0065] The present embodiments are to be considered in all respects asillustrative and no restrictive, and all changes which come within themeaning and range of equivalency of the claims are therefore intended tobe embraced therein. The invention may be embodied in other specificforms without departing from the spirit or essential characteristicsthereof.

What is claimed is:
 1. A corrugated fin comprising: a first and secondcorrugated fin portions having different fin widths corresponding to twotypes of heat exchangers and integrally formed next to each other, thefin width of said first corrugated fin portion being smaller than thefin width of said second corrugated fin portion; and a first and secondlouvers provided on each of said first and second corrugated finportions to extend corresponding to the fin widths of said first andsecond corrugated fin portions, said first and second louversrespectively having a plurality of louver slats inclined at apredetermined angle, said louver slats respectively having a directionof inclination which is different between each of said first and secondcorrugated fin portions, and a processed amount per unit width of saidsecond louver being smaller than a processed amount per unit width ofsaid first louver.
 2. A corrugated fin according to claim 1, wherein aninclination angle of said second louver on said second corrugated finportion is smaller than an inclination angle of said first louver onsaid first corrugated fin portion so that the processed amount per unitwidth of said second louver becomes smaller than said first louver.
 3. Acorrugated fins according to claim 1, wherein a pitch between adjacentlouver slats of said second louver formed on said second corrugated finportion is narrower than a pitch between adjacent louver slats of saidfirst louver formed on said first corrugated fin so that the processedamount per unit width of said second louver becomes smaller than saidfirst louver.
 4. A corrugated fin according to claim 2, wherein a pitchbetween adjacent louver slats of said second louver formed on saidsecond corrugated fin portion is narrower than a pitch between adjacentlouver slats of said first louver formed on said first corrugated fin sothat the processed amount per unit width of said second louver becomessmaller than said first louver.
 5. A corrugated fins according to claim2, wherein said first corrugated fin portion is for automotivecondensers, and said second corrugated fin portion being for automotiveradiators.
 6. A corrugated fin according to claim 2, wherein said firstcorrugated fin portion is for automotive condensers, and said secondcorrugated fin portion being for automotive radiators.
 7. A corrugatedfin according to claim 3, wherein said first corrugated fin portion isfor automotive condensers, and said second corrugated fin portion beingfor automotive radiators.
 8. A corrugated fin according to claim 4,wherein said first corrugated fin portion is for automotive condensers,and said second corrugated fin portion being for automotive radiators.9. A manufacturing method of a corrugated fin comprising: a louverprocessing step to form a first and second louvers in such a manner thaton each of a first and second corrugated fin portions have respectivelydifferent fin widths corresponding to two types of heat exchangers andintegrally formed next to each other, the fin width of said firstcorrugated fin portion being smaller than the fin width of said secondcorrugated fin portion, said first and second louvers extendingcorresponding to the fin widths of said first and second corrugated finportions and having a plurality of louver slats inclined at apredetermined angle respectively, said louver slats respectively havinga direction of inclination which is different between each of said firstand second corrugated fin portions, and a processed amount per unitwidth of said second corrugated fin portion is smaller than a processingamount per unit width of said first corrugated fin portion; and a bendcorrecting step to correct, after said louver processing step, a bend ofentire body of said first and second corrugated fin portions by wideningto a predetermined width a wave pitch inside a bending direction of saidfirst and second corrugated fin portions which are formed entirely in acorrugated form.